If even one opponent is open, you could easily burn out the other two, then swing in with an unstoppable Ob Nixilis to finish the job
A card with flash can be cast at any time you would use an instant
Another option is using something that can fill a party role and last through a board wipe think Bitterblossom, When building around Nalie, you will want to keep a high creature count to maximize your chance at reaching a full party but being able to search out the last party member you need is important and a card like Coveted Prize should certainly make the final cut
Decks that care about replaying lands and artifacts can get some use out of this artifact creature, but it suffers from being the an expensive version of this effect
Because if they are just: Everyone gets a mana of their choice, everyone gains 3 life, and then their ultimate is everyone draws seven cards, then they may not be the most powerful cards ever
theyll give you the chance to mill INTO a payoff even with none in hand